Various types of energy recuperating systems in chopper-controlled series motors are known. For example, it has been proposed to utilize series controlled motors driving, for example, electrically operated vehicles such as fork-lift trucks and the like, by returning energy from the motor, under dynamic braking conditions, to the storage battery. Upon initiation of braking, the field winding of the series motor is switched in polarity. At the same time, a transistor switch is opened which maintains field current to the field winding through a resistor. This system has the disadvantage that the resistor dissipates energy which is not being returned to the battery. The introduction of the resistor, further, causes the current pulses to be less peaked or, in other words, to flatten the current pulses, so that the actual feedback of energy does not commence immediately upon switch-over, but rather some time elapses before energy is fed back to the storage battery. See, for example, literature reference, "Bosch-Druckschrift B9/2, Impulssteuerungen", July 1980, ("Pulse Controllers"), page 17.